Temperature control switch structure



March 4, 1930. PENN 1,749,392

TEMPERATURE CONTROL SWITCH STRUCTURE Filed March 10, 1928 2 Sheets-Sheet1 March 4, 1930. A. PENN 1,749,392

TEMPERATURE CONTROL SWITCH STRUCTURE Filed March 10, 1928 2 Sheets-Sheet2 Patented Mar. 4, 1930 UNITED STATES PATENT OFFICE ALBERT PENN, OF DES-MOINES, IOWA, ASSIG-NOR TO PENN ELECTRIC SWITCH 00., OF

I DES MOINES, IOWA, A CORPORATION OF IOWA TEMPERATURE CONTROL SWITCHSTRUCTURE Application filed March 10, 1928. Serial No. 260,796.

The object of my invention is to provide a temperature control switchstructure of simple, durable, and comparatively inexpensiveconstruction.

A further object is to provide a structure of this character in which aswitch is controlled by a temperature actuated bellows element so thatan electric circuit may be es tablished or broken, depending on the tem-19 perature of the atmosphere surrounding the bellows element.

Another object is to provide such a device with a means for supportingthe bellows element and a spring mounted in opposition to the elementwhereby both the force of the spring and the element act upon theswitch.

Still a further object is to provide a lever for adjusting the tensionof the spring so that the switch will be actuated for making or breakingan electric circuit and the range of operation of the structure can bevaried by movement of this lever to any desired position.

Still a further object is to provide a base with a yoke on it forpivotally supporting a switch arm and for supporting the bellows elementin position to coact with the switch arm, the lever being mountedagainst the base and the spring associated therewith and mounted tooppose the bellows element.

Heretofore it has been customary, in devices of this character where thefurnace controlling mechanism is remotely controlled by a roomthermostat, to provide a pilot or relay circuit wherein the roomthermostat controls a small current which current in turn actuated arelay switch for controlling the heavier current required for operatingthe motor connected with the furnace dampers or the blower motor in anoil burner installation. In order to entirely eliminate the relaycircuit it has been my object to provide a switch adapted to easilycontrol the heavier current even when placed at a distance from themotor.

To accomplish this result I provide a switch in which the circuit isquickly broken for reducing the arcing at the contacts and by providingmain contacts for carrying most of the current when the switch is closedand auxiliary contacts for temporarily carrying the current for aninstant as the circuit is made or broken, the auxiliary contacts beinglocated in a magnetic field, the arcing is still further reduced andalmost entirely eliminated.

It has therefore been a further object to provide a means associatedwith the switch arm for causing this quick action of the arm when theelectric circuit is being made or broken whereby the entire controllingcircuit may be carried by my device without the use of a pilot circuit.

With these and other objects in view my invention consists in theconstruction, arrangement and COHlbllliltiOIiOf the various parts of mydevice, whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claims and illustrated in theaccompanying drawings. Although the invention is susceptible of avariety of embodiments, it is unnecessary to fully describe andillustrate more than one in order to give a full understanding of theinvention both from its structural and functional standpoints.Accordingly, I have illustrated a preferred and desirable embodi-- mentof the invention in the accompanying drawings in which:

Figure 1 is a front elevation of my device showing its appearance wheninstalled on a wall in a living room or the like whereby it may beoperated according to the temperature in the room.

Figure 2 shows a side elevation of my device.

Figure 3 is an enlarged sectional View on the line 3-3 of Figure 1..

Figure 4 shows a portion of Figure 3 with the parts thereof in adifferent position.

Figure 5 is a view similar to Figure 4,

showing the parts in still another position.

and illustrating in connection with the device an electric circuitcontrolled by the switch.

Figure 6 is a sectional view on the line 66 of Figure 3 illustratin thesupporting yoke for the bellows and spring and the relation of theseparts to each other.

Figure 7 is a sectional view on the line 7-7 of Figure 4 illustrating aportion of the switch structure; and

Figure 8 is a sectional view on the line 88 of Figure 6 showing theoperating lever for varying the differential of operation of thetemperature actuated bellows.

On the accompanying drawings I have used the reference numeral 10 toindicate a base. The base 10 supports the various parts of my structureand is designed to be attached to a wall by screws or other means. Thebase 10 has secured to its back side a conduit box 12 which may beconcealed in a depression in the wall to which the base is secured forthe purpose of housing electrical connections to the switch of mystructure.

A yoke 14 is secured to the base 10 by means of screws 16 extending intofeet 18 formed on the yoke. The yoke 14 is provided with a pair ofprojections 20.

v A yoke shaped switch arm 22 is pivoted in the yoke 14 by pins 24extending rotatably into openings formed in the extensions 20. Securedto the arm 22 is an armature 26 adapted to support a main contact 28 andan auxiliary contact 30. The auxiliary contact 30 is mounted through anopening 32 formed in the armature 26 and is supported by a leaf spring34 riveted to the armature 26 and the arm 22.

Secured to the base 10 is a block 36 of insulating material adapted tosupport a permanent magnet 38. The magnet 38 is held in position by aclip 40. The clip 40 supports a fixed auxiliary contact 42 adapted tocoact with the contact 30. Secured to the block 36 is a fixed maincontact 44 adapted to coact with the contact 28. The contacts 42 and 44are connected together b a connector 46 as illustrated in Figure 3 o thedrawings.

A flexible lead 48 is secured to a terminal 50 on the block 36 and hasits free end secured to the armature 26 whereby the contacts 28 and 30are electrically connected to a wire 52. A wire 54 extends from theterminal screw 57 and these two wires may be included in any electriccircuit adapted to be controlled by the structure herein disclosed. Byway of a 56 by means of the switch device thus far described, I providea washer 62 having a notch 64 adapted to loosely receive a pin 66extending from side to side of the yoke shaped arm 22 as bestillustrated in Figure 6 of the drawmgs.

Secured tothe washer 62 is a bellows element 68 which is entirely sealedand provided with a head 70. The head 70 has secured thereto asupporting bolt 72 extending through the yoke 14. Adjusting nuts 74 arepositioned on the bolt 72 on each side of the yoke 14 so that theposition of the bellows element 68 can be initially adjusted at thefactory for proper temperature operation. The washer 62 is provided witha flange 76.

Extending from the base 10 is a post 78, the end of which engages thewasher 62 and acts as a limit stop for the washer in one direction. Asecond washer is slidably but non-rotatably mounted on the post 78 and aspring 82 is interposed between the washers 62 and 80. A shoulder isformed on the washer 80 for positioning the spring 82 thereon and theflange 76 serves the same purpose on the washer 62. It will be obviousthat various positions of the washer 80 on the post 78 will causedifferent tensions of the spring 82 in opposition to the bellows element68 so that the range of the operation of the bellows may be variedaccording to the wishes of the operator.

For adjusting the washer 80 relative to the post 78 I provide thefollowing described mechanism.

A cam surface 84 is formed on the washer 80. A lever 86 best shown inFigure 8 of the drawings is pivoted on a shouldered bolt 88 extendinginto the base 10. The lever 86 is provided with an are shaped opening 90so that the post 78 does not interfere with its swinging movement. A camsurface 92 is formed on the lever 86 adapted to coact with thecamsurface 84 of the washer 80.

From the foregoing construction it will be obvious that swingingmovement of the lever 86 will either impose additional tension on thespring 82 or reduce that tension depending on which way the lever 86 isswung. A pointer 94 is formed on the lever 86 which serves inconjunction with a scale 96 on the base 10 to indicate the degree ofheat for which the device is set. a

In connection with my device I provide a cover member 102 for housingthe switch structure and the bellows element. An extension 104 isprovided for extending over the bellows element and the yoke 14. Thecover member 102 is provided with flanges 106 extending over the sidesof the base 10 and secured thereto by screws 108.

The cover member 102 and the extension 104 are provided with openings110 for allowing the atmosphere temperature of the room to affect thebellows element readily.

A slot 112 is formed in the cover member through which the controllinglever 86 p l trudes so that it can be manipulated by an operator of thedevice.

If desired, a thermometer 114 can be mounted on the outside of the cover102 for the purpose of indicating the temperature of the IOOIII.

Practical operation In the operation of my device, the lever 86 is setfor the degree of heat desired to be maintained, for instance in aliving room. Thereafter the switch operates automatically for eitherstartin the motor 56 or stopping it depending on t e demands for anincrease in temperature or for a reduction in temper ature. Assuming theswitch to be in open position as illustrated in Figure 3, a reduction ofthe temperature affecting the bellows 68 will allow the armature 26 tomove in the direction of the arrow 98 due to the tension of the spring82. When the armature is close enough to the magnet 38 the attraction ofthe magnet will cause the contact to quickly contact with the contact 42as shown in Figure 4 and the armature will be moved still farthercausing the contact 28 to touch the contact 44 for establishing theelectric circuit through both the main and auxiliary contacts as shownin Figure 5. When the temperature in the room increases above apredetermined point, the armature 26 will be moved in the direction ofthe arrow 10o first breaking the main contact as shown in Figure 4 andthen the auxiliary contact. The

Y breaking of the auxiliary contact occurs in the iii) magnetic field sothat any tendency tospark ing is immediately blown out by the action ofthe magnetic field.

The bellows 68 when the switch is opening accumulates a slight amount ofenergy in trying to overcome the magnetic field of the magnet 38. Assoon as the armature 26 starts to move out of the strongest magneticfield, however, it immediately comes into a weaker field and at the sametime the storedup energy operates on the switch arm for quickly breakingthe contact which aflords and gives a snap action which is verydesirable in a'switch of this kind. To further facilitate the action ofthe switch, the notch 64 is somewhat wider than the diameter of the pin66, as shown in dotted lines in Figure 6, so that when the magnet 38does'afi'ect the arm 26', the lost motion between the notch and the pinwill allow slight move ment of the arm independent of the bellows 68 andspring 82.

Some changes may be made in the construction and arrangement of thevarious parts of my invention, without departing from the real spiritand purpose of my invention, and it is my intention to cover by myclaims, any

modified forms of structure or use of mechan ical equivalents which maybe reasonably in eluded within their scope.

I claim as my invention: 1. A structure of the character disclosedcomprising a stationary contact, a yoke, a

movable armature pivoted thereto, a contact.

carried by said armature and adapted to enage the stationary contactwhen the armature 1s m one position of its movement, a magnet,

said armature being in close proximity to said magnet when in suchposition whereby a snap action switch is provided, a bellows having oneend anchored to said yoke and its other end acting upon said armaturefor moving it in one direction and a spring opposing the action of saidbellows.

2. A structure of the character disclosed comprising a stationarycontact, a movable armature, a contact carried thereby and adapted toengage the stationary contact when the armature is in one position ofits movement, a magnet, said armature being in close prox imity to saidmagnet when in such position whereby to cause quick action of thearmature a spring associated with said armature for moving it to suchposition and a bellows opposing said spring and expandible upon anincrease of temperature of the surrounding atmosphere, one end ofsaidspring being slidable longitudinally relative to the axis thereofwhereby to vary the action of the bellows on the armature and means forlocking such end of the spring in any of the positions to which it maybe slid.

3. In a temperature controlled switch strncture, a base, a switchmounted thereon and including a fixed and a movable contact, an arm forsupporting said movable contact, means associated with said arm forcausing it to move quickly as the contact thereon is being separatedfrom the fixed contact, a yoke mounted on said base, said arm beingpivoted to said yoke, a temperature influenced bellows carried by saidyoke and acting upon said arm for moving the same, a sprin counteractingthe bellows, a post on said base and arranged on the axis line of saidspring, a member longitudinally slidable relative to said post, a leverpivoted to said base at a point spaced from said post, and coacting camsurfaces on said lever and on said member. a

4. In a temperature controlled switch structure, abase, a switch armpivotally mounted thereon, a temperature influenced bellowls carried andacting upon said arm for moving the same, a spring counteracting thebellows,

1 and means for adjusting the tension of said spring, said meanscomprising a member against one end of said spring, said member beingslidable longitudinally relative to the axis of said spring butnon-rotatable, a cam surface on said member; and a swingable adjustinglever having acam surface for coac- -tion with the cam surface of saidmember.

5. In a temperature controlled switch structure, a base, a switchmounted thereon and including a fixed and a movable contact, means forcausing a quick separation of said contacts whereby the entire currentof a circuit may be controlled without a relay circuit, an arm forsupporting said movable contact, a yoke mounted on said base, said armbeing pivoted to said yoke, a temperature influenced bellows carried bysaid yoke and acting upon said arm for moving the same, a spring counteracting the bellows and means for adjusting the tension of saidspring, said means comprising a washer against said spring. a camsurface on said washer, a lever pivoted at a point spaced from the axisof said washer and a cam surface on said lever for coacting with the camsurface on the washer.

6. A device of the kind described comprising a base, a yoke supportedthereby, a switch arm pivoted to said yoke, a pin extending from saidswitch arm, a notched washer, a spring on one side thereof, a bellows onthe other side thereof, the notch in said washer 'receiving said pinwhereby expansion and contraction of the bellows will move said switcharm.

7. A device of the kind described comprising a base, a yoke supportedthereby, a switch arm pivoted to said yoke, a pin extending from saidswitch arm, a notched washer, a spring on one side thereof, a bellows onthe other side thereof, the notch in said washer receiving said pinwhereby expansion and contraction of the bellows will move said switcharm and cam means for varying the adjustment of said spring for changingthe setting of said device.

8. A device of the kind described comprising a base, a yoke supportedthereby, a switch arm pivoted to said yoke, a pin extending fromsaidswitch arm, a notched washer, a spring on one side thereof, a bellows onthe other side thereof, the notch in said washer receiving said pinwhereby expansion and contraction of the bellows will move said switcharm, a second washer against the free end of said spring, a postextending from said base, said second washer being slidably mountedthereon.

9. A device of the kind described comprising a base, a yoke supportedthereby, a switch arm pivotedto said yoke, a pin extending from saidswitch arm, a notched Washer, a spring on one side thereof, a bellows onthe other side thereof, the notch in said washer receiving said pinwhereby expansion and contraction of the bellows will move said switcharm, a second washer against the free end of said spring, a postextending from said base, said second washer being slidably mountedthereon and means for locking said washer at any position thereon, saidmeans comprising a lever having cam means for coacting with said secondwasher.

10. A device of the kind described comprising a base, a yoke supportedthereby, a switch arm pivoted to said yoke, a pin extending from saidswitch arm, a notched washer, a spring on one side thereof, a bellows onthe other side thereof, means for adjusting said bellows relative tosaid yoke, the notch in said washer receiving said pin whereby expansionand contraction of the bellows will move said switch arm, a secondwasher a ainst'the free end of said spring, a post extendin from saidbase, said second washer being slidably mounted thereon.

11. A device of the kind described compris-, ing a base, a yokesupported thereby, a switch arm pivoted to said yoke, a pin extendingfrom said switch arm, a notched washer, a spring on one side thereof, abellows on the other side thereof, the notch in said washer receivingsaid pin whereby expansion and contraction of the bellows will move saidswitch arm, a second washer against the free end of said spring, a postextending from said base, said second washer being slidably mountedthereon, means for locking said washer at any position thereon, saidmeans comprising a lever having cam means for coacting with said secondwasher, and a scale associated with said lever for indicating thedesired temperature at which the device is to be set for operation.

12. In a temperature controlled device, a movable arm, a temperatureinfluenced bellows acting upon said arm for moving the same, a springcounteracting the bellows and means for adjusting the tension of saidspring, said means comprising a member engaging said spring, said memberbeing slidable and non-rotatable and cam mechanism for moving saidmeans.

Des Moines, Iowa, December, 1927.

ALBERT PENN.

